A pilot cohort study of lumbar facet joint denervation in patients with chronic low-back pain.

ABSTRACT

INTRODUCTION: Radio-frequency (RF) denervation of the facet joints is a procedure aimed at the nociceptive median branch nerves of the lumbar dorsal rami. Pain signals from the facet joints are carried through these fibres; by ablating these fibres, central signalling can be prevented. This pilot study investigated the clinical effect and feasibility of the procedure at our institution, the Spine Centre of Southern Denmark. METHODS: Patients with at least 50% pain relief after initial medial branch diagnostic blocks were candidates for RF denervation. Patients were divided into two groups 1) patients with at least 80% pain relief and 2) patients with between 50% and 79% pain relief after diagnostic blocks. Denervation was performed bilaterally on the three lowest facet joints in the lumbar spine. The primary outcome parameter was visual analogue scale (VAS). Follow-up questionnaires were answered after one week and after three, six and 12 months. RESULTS: For the whole sample, we found a mean reduction of 43 VAS points after one week. At three months, we found a mean reduction of 25 points. Six-month data showed a mean 19-point reduction. Twelve-month data showed a mean reduction of 17 points. Group 1 showed superior improvements at all follow-up points and after 12 months, we found a mean VAS reduction of 22 points for this group. CONCLUSIONS: This pilot cohort study found RF denervation of the facet joint to be a promising alternative for patients with chronic low-back pain. The effect persisted at the one-year follow-up; however, the effect diminished over time. FUNDING: The Danish Rheumatism Association, The A.P. Møller Foundation for the Advancement of Medical Science. TRIAL REGISTRATION The study protocol was approved by the ethical committee of Southern Denmark with registration number S-20160070.